The invention relates to a safety-closure device of the variety in which a cupped closure cap has thread-on, thread-off engageability with respect to the neck of a bottle or other container.
For child-safety purposes, it is desirable that such closure devices shall require an additional actuation, i.e. other than merely an un-threading rotation, in order to dislodge the cap from the container neck. Prior devices of this general character have relied on plural angularly spaced self-locking bayonet engagements wherein only a relatively small cap-to-neck rotation is operative to make the closing engagement; such devices have used squeezability, axially compliant compressed displacement and axially compliant tensed displacement as the various additional actuations needed to effect release from a locked closed position. But we have no knowledge of a satisfactory additional unlocking actuation such as a push-to-release actuation, embodied in a full-thread cap-to-neck engagement, i.e. an engagement involving at least one full turn of threaded engagement.